Home Forums Hunting & Shooting Ask The Gunwriters MRP vs RL22?

Does anyone know if it is true that Norma MRP and Alliant Reloader 22 are the same powder?
I had heard rumor of someone mentioning that being the case but wanted to verify before I started load development for my 7 SAUM with Berger 168’s.
Looking to get between 2800-2900 on velocity and this seems to fit the bill.

Thanks

Well, after looking at more than a couple of burn rate charts if they are not one and the same, then they are kissing cousins.

Yup, used them grain for grain over the last 15 years. The book shows ~.5 grains difference but haven't found that to be the case in my usage.

Thanks guys,
Just found some weird data on loaddata.com showing some large differences between them for the load I want to develop for my .280 and my 7 SAUM.
Thought it best to check on that.

Have a great night!

anyone loading 180 gr. Nosler Partitions with RL.22 ? I have new Remington cases that i can`t hardly get 58 gr.s of powder in so i loaded down to 57 grs. of RL.22 powder. i want to use these bullets and new Remington brass cases in my Remington paper ammo 20 rd. boxes because i am going to Africa so i want my newly loaded ammo look like factory ammo, so i have no problems at air ports. thank you ,Pete53

I use them interchangeability across several different cartridges; some say they are the same, same say not.

They've always looked a little different color to me with MRP being darker while '22 has always been more grayish.

MM

Have posted this before, but when this question first came up on the Campfire a while back I had recent batches of both. Could not see any difference in appearance, whether granule size or color, and tried both with the same load--if I recall correctly in a .270 Winchester. Both got the same velocity within around 20 fps, and the same groups--which landed in the same place at 100 yards.

That may have changed, but wasn't very impressed with either powder's temperature resistance--which is important to me here in Montana--so haven't worked up any loads in my hunting rifles with either since then. Though always included them where appropriate in various articles....

Well, I had not considered the temp tolerance of it.
Maybe I will look into 4831sc or 7828 ssc instead.

Thanks for the thought John.

I haven't used RL-22 for a while as I no longer have rifle-cartridges for which it's appropriate. But for a long time I used it in numbers like 7 mags, .300 mags and my .340 Wby. Never noticed much change due to outside temps, though I'd heard about it. It was the most accurate and with the highest MVs in those rifles. At one time I used MRP but thought it a bit slower than RL-22.

Bob
www.bigbores.ca

I did find considerable difference in results with RL-22 between 70 and zero degrees Fahrenheit, as reported in various publications, including Chapter 10 of The Big Book of Gun Gack II--which includes my testing of 15 cartridges from the .17 Hornady Hornet to .375 H&H with a bunch of different powders.

But also pointed out that such variations depend on the cartridge, load, and other factors such as primer, compression of the loads, etc. And the biggie is whether they change point of impact, which also depends on the rifle itself, including barrel contour, bedding, etc.

Also pointed out that such variations often don't make much difference in shooting big game at "normal" ranges, since the vital area of big game is by definition is a larger target than most. But it can....

The biggest POI change I’ve ever experienced when cold weather testing was with RL22, a pair of 270’s, and 150g NPt’s.

What was your work up load temp and the cold weather temp Casey?

Just checked my notes. I worked up loads in temps from 50-77 degrees. When I prepare for temp stability testing I load 22 rounds (couple extra in case), shoot a 10 shot string during warm weather (in this case it was 79 degrees) and then wait for single digit weather for the cold testing. I started at 1 degree on that day with the RL22.

Casey,

When I first started testing powders in cold temps around 30 years ago, the two initially tested were mil-surp H4831 and RL-22. Have related why in several articles and books, and posts here, but had worked up loads with each powder in a Remington .270 Winchester at "normal" temperatures, using 130 and 150-grain bullets. The two loads shot to the same 100-yard point of impact at around 70 degrees, and grouped very well.

But at around zero they both changed considerably. The H4831/130 load shot to the same place, but 3-shot groups opened up to almost two inches. The RL-22/150 load grouped about the same as at 70 degrees, but the 100-yard POI shifted right 3 inches!

John,
In the time I’ve been testing temp stability of powders, H4831 and H4350 have always been temp stable, including the pre Extreme designation. I’m sure somewhere there is a load or two with those powders that is temp sensitive, but I nor a couple friends who also test have found it.

I have been told the VV 100 series of powder can be counted on to be temp stable also.

Pretty darn close.

[quote=alpinecrick]John,
In the time I’ve been testing temp stability of powders, H4831 and H4350 have always been temp stable, including the pre Extreme designation. I’m sure somewhere there is a load or two with those powders that is temp sensitive, but I nor a couple friends who also test have found it.

I have been told the VV 100 series of powder can be counted on to be temp stable also.[/quote

As of 2-3 years ago ALL Vihtavuori powders became temp-resistant, and also contain a decoppering agent.

When did you start temp-testing? If I recall correctly, the Extreme version of H4831 appeared during the 1990s, but can't remember if it was called that at first--or if the only change noted on the containers said "Made in Australia." H4350 was always the temp-stable version from Australia.

A lot of changes were being made in Hodgdon powders then, because they were running out of the mil-surp powders. H335, BL-C2 and maybe one other were lots of the same basic powder with somewhat different burn rates. Found this out by buying some H335 in 1992, as I'd run out my previous batch. Loaded the same charge and bullet in a very accurate 700 BDL sporter .223 I had back then, and it blew a primer. Had to drop the charge a grain and a half to match the velocity with the previous batch--and mentioned this in an article.

Rob Reiber, for many years the head ballistician at Hodgdon, contacted me and said the powder I'd just purchased was newly-manufactured, not the mil-surp stuff. He was in the process of updating their data, which in those days took far longer to appear than today, because it didn't change until the next book edition of their manual was printed--unlike today when new data appears very quickly on the Internet.

Learned a LOT about powders from Ron, and miss my frequent discussions with him after he retired a few years ago. (Which he richly deserved, and is having far more fun bird-hunting now....)

They are completely interchangeable, at least in my experiences across a variety of Weatherby calibers (using load data from the old Weatherby Guides), 257,7MM, 300 & 340,

I actually recently found I had an older 5lb jug of RL22...not even sure where I picked it up, but it was within the last year or so. I *think* my goal was to use it in .25-06, 6mm Rem, and 7mm Rem Mag.

Both MRP and Reloader 22 are made by Eurenco/Bofors in Sweden. Looking through the various reloading manuals burn rate charts these two powders tend to be listed side by side but some books list Reloader 22 with a faster burn rate and other books have MRP listed as the faster powder.